What is the price difference on the mobo if i were to go xfire instead of sli?
i'm currently running thermaltake purepower 600w, i'm also wondering if that is enough juice

For Crossfire, an Intel X38 or X48 is suggested. DFI makes a popular one for around $180 on Newegg.

I'm going to be quite blunt but not to the point I want to offend anyone. If I do I assure you it's unintentional. I see a lot of people that get bit by the SLi bug that eventually choose a less than ideal motherboard (i.e. too expensive, not a good value compared to other alternatives, history of problems, etc.) with the intention of having the SLi upgradeability. If you eventually do buy that second card then great; you are pretty much ready to go. I firmly believe though that you will find a motherboard like the Gigabyte DS3L that someone else suggested will bring you much more happiness in the long run. I'd also be willing to bet that if you bought any card better than a 9600GT, you'd find the performance is adequate for the games you'll end up playing (unless you are playing Crysis and/or have a hi-res monitor). Should a time come that that 9600 (or whatever you end up with) doesn't cut it, Step-Up (EVGA) to something else within 90 days or sell it and buy something else.

Not sure about that PSU. Someone a little more savvy will have to answer that one.

I ditched a perfectly capable Asus P5B Deluxe and bought a 680i so I could run SLi. Why? Because I wanted to. What a mistake that was. I ended up going though multiple boards and found them much harder to stabilize than that old school Intel they replaced. I finally got to the point where I said frock it and went back to a nice Intel motherboard and a single high-end card.Edited by MNiceGuy - 5/28/08 at 12:25am

Sure, a P35 chipset MIGHT (actually will) allow for slightly higher clocks with lower voltages, but that extra 200MHz is easily beaten out by an extra card running in tandem... to many, that little aspect is very tempting

The simple solution:
A used EVGA 680i SLI... they're great OCers and very nice boards - the only real fault with them is a few quirks w/ quad cores... but the guy is ocing a DUAL CORE... get a cheap AR or TR revision (not as quad core friendly as the A1s and T1s, but just as good for duals) cheap off someone here on OCN (I think i saw one for $85ish awhile back) and you should end up very satisfied - they'll clock up a core 2 duo just as well as a P35

Regardless of my suggestion, these guys do have a point... if you're willing to consider a single card system and if you believe there to be that chance that you'll end up buying that next gen card instead of another card to SLI - the P35s are very affordable and very OC friendly and should be given some consideration Edited by killa_concept - 5/28/08 at 12:31am

For Crossfire, an Intel X38 or X48 is suggested. DFI makes a popular one for around $180 on Newegg.

I'm going to be quite blunt but not to the point I want to offend anyone. If I do I assure you it's unintentional. I see a lot of people that get bit by the SLi bug that eventually choose a less than ideal motherboard (i.e. too expensive, not a good value compared to other alternatives, history of problems, etc.) with the intention of having the SLi upgradeability. If you eventually do buy that second card then great; you are pretty much ready to go. I firmly believe though that you will find a motherboard like the Gigabyte DS3L that someone else suggested will bring you much more happiness in the long run. I'd also be willing to bet that if you bought any card better than a 9600GT, you'd find the performance is adequate for the games you'll end up playing (unless you are playing Crysis and/or have a hi-res monitor). Should a time come that that 9600 (or whatever you end up with) doesn't cut it, Step-Up (EVGA) to something else within 90 days or sell it and buy something else.

Not sure about that PSU. Someone a little more savvy will have to answer that one.

those are some good points that you've mentioned. I'm not a hardcore gamer, I don't think I'll be using the potential of xfire or sli. I always like the idea of being able to upgrade simply adding another video card than upgrading the mobo and video card. I'll think about what you guys suggested. Thank you for your valuable comments.

those are some good points that you've mentioned. I'm not a hardcore gamer, I don't think I'll be using the potential of xfire or sli. I always like the idea of being able to upgrade simply adding another video card than upgrading the mobo and video card. I'll think about what you guys suggested. Thank you for your valuable comments.

You will get much better performance by just getting a new card. Adding another card for SLi gives a minimal performance gain.

Sure, a P35 chipset MIGHT (actually will) allow for slightly higher clocks with lower voltages, but that extra 200MHz is easily beaten out by an extra card running in tandem... not to say that single card solutions aren't cheaper and effective and that p35 boards aren't great affordable OCing boards (hell, I just snagged a Blood Iron awhile back)...

The simple solution:
A used EVGA 680i SLI... they're great OCers and very nice boards - the only real fault with them is a few quirks w/ quad cores... but the guy is ocing a DUAL CORE... get a cheap AR or TR revision cheap off someone here on OCN (I think i saw one for $85ish awhile back) and you should end up very satisfied - they'll clock up a core 2 duo just as well as a P35

But these guys do have a point... if you're willing to consider a single card system, P35s are very affordable and very OC friendly

Good points but consider this:

System A: Intel P35 and 9600GT
System B: Nvidia 680i and a pair of 9600GTs

The key here is that we are on a budget (the OP did not explicitly say so but the $100 mobo budget suggests it). System A will get the job done on an average sized monitor. System B is more powerful but is it really THAT much more powerful? SLi and Crossfire both share the same quality: they both have horrible price to performance ratios.